Various connection devices are available to establish electrical contact between an electrical wire and a solar panel. Solar panels themselves are photovoltaic devices that convert incident solar radiation from the sun into electrical energy. Each solar panel comprises a plurality of modules typically connected in series within a frame. A plurality of panels may be connected together to form a solar panel array. The plurality of modules are connected together to form a solar panel, and a plurality of solar panels are connected together to form a solar panel array. When connected in series, the voltages of the modules are additive. Of course, diodes typically are included in such solar panels arrays to permit the flow of electrical energy in only one direction, thereby preventing damage to the panel.
An electrical connector that is mounted on or adjacent to a solar panel enables and facilitates the connection of the panel to ground, completing an electrical circuit from the panel to ground. While various grounding connectors are utilized, one of the most utilized is the copper lug design. This prior art design is shown in FIG. 1. The copper lug is relatively simple, comprising a C-clamp shape having a horizontal extension. The copper lug itself is extruded. Two apertures are located in the extrusion, the first located in the top of the C-portion of the clamp and the second in the horizontal extension. The second aperture on the horizontal extension allows the lug to be assembled to the solar panel, establishing electrical contact between the solar panel and the lug, a screw passing through the second aperture fastening the lug to the panel. A flat-bottomed screw passes through a threaded hole in the first aperture. The wire that connects two or more arrays is passed through the cradle in the “C” of the C-clamp. The flat-bottomed screw is then turned down onto the wire to capture the wire in the base of the “C”. While of simple design, the assembly of the wire to the C-clamp is labor-intensive. Each clamp must be assembled to the solar panel frame, the wire passing through the cradle in the C-clamp must be stripped and the flat-bottomed screw must be torqued against the stripped wire to establish a firm electrical connection with the wire.
One potential problem with this design is that the flat-bottomed screw can work its way loose, even when properly torqued during initial assembly. The temperatures experienced by a solar panel can vary significantly, not only from day to night, but also as clouds block solar energy from the sun. The repeated differential thermal expansion among the screw, the wire and the lug can cause the stresses among these parts to be relieved. Over a period of time, if sufficient movement occurs, the electrical contact can become intermittent or can cease to exist. In addition, if the screw used to fasten the lug to the solar frame is of a metal that is not compatible with the lug, galvanic corrosion can occur which could result is a loosening of the lug from the solar frame, which also can result in an intermittent contact.
What is required is a simple connection that permits the assembly of a connector to a solar module frame and rapid assembly of a wire to the connector, thereby allowing solar frame or plurality of frames to be grounded rapidly and reliably.